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Full text of "Metallurgy Of Cast Iron"

330                       METALLURGY   OF   CAST   IRON.
analyses were all taken from the blocks as they came from the first casts of the original pig or scrap metal.
In all the heats the hard iron is seen to have come down first, excepting in one case which is found in heat No. 6, and that the flow of hard iron ended soonest in all the heats. Thus, as far as these tests go they show that hard iron will melt faster than soft, and confirm my past assertions and the general impression existing among old experienced founders that hard iron will melt more readily than soft grades.
An interesting discussion followed the reading of the paper. Dr. Richard Moldenke contributed the following: '' Long experience with the melting of iron in Siemens-Martin furnaces having given me the impression that hard irons melt faster than soft ones, and knowing this to be the accepted view among the trade, I was not a little astonished to see claims advanced insisting on the contrary. At the time I thought it likely to be owing to some radical difference in the composition of the irons that were used, and was therefore more than pleased to hear Mr. West advance the idea of making comparative tests to settle the matter definitely. It has remained for him to devise a most excellent system of melting to accomplish this result, and I, for one, have been much interested in the working of his " twin shaft cupola " (Fig. 56), if I may so call it. It will give us ready means of comparing the fusibility of the required brands of iron going into our cupola charges. The few words I have to add relate to the melting of iron in the open-hearth furnace, where there is obviously no difficulty due to the rate of melting, since everything charged is supposed to make up a bath of uniform composition. I of a soft iron used as a comparative constant to the hard irons throughout the eight heats. It may be stated that drillings for45 s.	i m.	10 s.	45 s.	i m.	15 s.	nil 3os	nn 458